第八周项目二：Time类中的运算符重载

问题：



实现Time类中的运算符重载。

参考代码：

class CTime
{
private:
    unsigned short int hour;    // 时
    unsigned short int minute;  // 分
    unsigned short int second;  // 秒
public:
    CTime(int h=0,int m=0,int s=0);
    void setTime(int h,int m,int s);
    void display();
    //二目的比较运算符重载
    bool operator > (CTime &t);
    bool operator < (CTime &t);
    bool operator >= (CTime &t);
    bool operator <= (CTime &t);
    bool operator == (CTime &t);
    bool operator != (CTime &t);
    //二目的加减运算符的重载
    //返回t规定的时、分、秒后的时间
    //例t1(8,20,25),t2(11,20,50)，t1+t2为19:41:15
    CTime operator+(CTime &t);
    CTime operator-(CTime &t);//对照+理解
    CTime operator+(int s);//返回s秒后的时间
    CTime operator-(int s);//返回s秒前的时间
    //二目赋值运算符的重载
    CTime operator+=(CTime &c);
    CTime operator-=(CTime &c);
    CTime operator+=(int s);//返回s秒后的时间
    CTime operator-=(int s);//返回s秒前的时间
};

解决代码：

#include <iostream>
using namespace std;
class CTime
{
private:
    unsigned short int hour;    // 时
    unsigned short int minute;  // 分
    unsigned short int second;  // 秒
public:
    CTime(int h=0,int m=0,int s=0);
    void setTime(int h,int m,int s);
    void display();
    //二目的比较运算符重载
    bool operator > (CTime &t);
    bool operator < (CTime &t);
    bool operator >= (CTime &t);
    bool operator <= (CTime &t);
    bool operator == (CTime &t);
    bool operator != (CTime &t);
    //二目的加减运算符的重载
    //返回t规定的时、分、秒后的时间
    //例t1(8,20,25),t2(11,20,50)，t1+t2为19:41:15
    CTime operator+(CTime &t);
    CTime operator-(CTime &t);//对照+理解
    CTime operator+(int s);//返回s秒后的时间
    CTime operator-(int s);//返回s秒前的时间
    //二目赋值运算符的重载
    CTime operator+=(CTime &c);
    CTime operator-=(CTime &c);
    CTime operator+=(int s);//返回s秒后的时间
    CTime operator-=(int s);//返回s秒前的时间
};
CTime::CTime(int h,int m,int s)
{
    hour=h;
    minute=m;
    second=s;
}
void CTime::setTime(int h,int m,int s)
{
    hour=h;
    minute=m;
    second=s;
}
void CTime::display()
{
    cout<<hour<<":"<<minute<<":"<<second<<endl;
}
bool CTime::operator < (CTime &t)
{
    if(hour<t.hour) return true;
    if(hour>t.hour) return false;
    if(minute<t.minute) return true;
    if(minute>t.minute) return false;
    if(second <t.second) return true;
    return false;
}
bool CTime::operator > (CTime &t)
{
    if(hour<t.hour) return false;
    if(hour>t.hour) return true;
    if(minute<t.minute) return false;
    if(minute>t.minute) return true;
    if(second <t.second) return false;
    return true;
}
bool CTime::operator >= (CTime &t)
{
    if (*this < t) return false;
    return true;

}
bool CTime::operator <= (CTime &t)
{
    if (*this > t) return false;
    return true;

}
bool CTime::operator == (CTime &t)
{
    if (*this < t || *this > t) return false;
    return true;

}
bool CTime::operator != (CTime &t)
{
     if (*this == t) return false;
     return true;

}
CTime CTime::operator+(CTime &t)
{
    int h,m,s;
    s=second+t.second;
    m=minute+t.minute;
    h=hour+t.hour;
    if(s>59)
    {
        s-=60;
        m++;
    }
    if(m>59)
    {
        m-=60;
        h++;
    }
    if(h>23)
    {
        h-=24;
    }
    CTime t0(h,m,s);
    return t0;
}
CTime CTime::operator-(CTime &t)
{
    int h,m,s;
    s=second-t.second;
    m=minute-t.minute;
    h=hour-t.hour;
    if(s<0)
    {
        s+=60;
        m--;
    }
    if(m<0)
    {
        m+=60;
        h--;
    }
    if(h<0) h+=24;
    CTime t0(h,m,s);
    return t0;
}
CTime CTime::operator+(int s)
{
    int ss=s%60;
    int mm=(s/60)%60;
    int hh=s/3600;
    CTime t0(hh,mm,ss);
    return *this+t0;
}
CTime CTime::operator-(int s)
{
    int ss=s%60;
    int mm=(s/60)%60;
    int hh=s/3600;
    CTime t0(hh,mm,ss);
    return *this-t0;
}
CTime CTime::operator+=(CTime &c)
{
    *this=*this+c;
    return *this;
}
CTime CTime::operator-=(CTime &c)
{
    *this=*this-c;
    return *this;
}
CTime CTime::operator+=(int s)//返回s秒后的时间
{
    *this=*this+s;
    return *this;
}
CTime CTime::operator-=(int s)//返回s秒前的时间
{
    *this=*this-s;
    return *this;
}

int main()
{
    CTime t1(8,20,25),t2(11,20,50),t;
    cout<<"t1为：";
    t1.display();
    cout<<"t2为：";
    t2.display();
    cout<<"下面比较两个时间大小：\n";
    if (t1>t2) cout<<"t1>t2"<<endl;
    if (t1<t2) cout<<"t1<t2"<<endl;
    if (t1==t2) cout<<"t1＝t2"<<endl;
    if (t1!=t2) cout<<"t1≠t2"<<endl;
    if (t1>=t2) cout<<"t1≥t2"<<endl;
    if (t1<=t2) cout<<"t1≤t2"<<endl;
    cout<<endl;
    t=t1+t2;
    t=t1-t2;
    t=t1+2000;
    t=t1-5000;
    t1+=t2;
    t1-=t2;
    t1+=2000;
    t1-=5000;
    return 0;

}

运行结果：

学习心得：可以进行时间类的比较和运算了！